The Prime Video app-or channel, as Roku calls its apps-does not come pre-installed on Roku devices, but it is not a difficult task to install it. How to install Amazon Prime Video on Roku You will need a Prime Video subscription in order to watch most of the content, though many movies and series are available to rent or buy individually without a subscription.
Yes, it is possible to access Amazon Prime Video on Roku, gaining access to all its content via any Roku device, whether you own the Roku Streaming Stick+, the Roku Ultra, or Roku's 4K streaming device, the Roku Premiere.
At Amazon Is Amazon Prime Video on Roku yet?